fixed bug in ctype where the existential type declaration was not added to the environment
fixed bug in ctype where the existential type declaration was not added to the environment

git-svn-id: 37248319af6e851e9168804c9b74d2ea80b9c036@10710 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

msprotz/ocaml,gerdstolpmann/ocaml,eliberis/ocaml,msprotz/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,eliberis/ocaml,eliberis/ocaml,msprotz/ocaml,eliberis/ocaml,gerdstolpmann/ocaml,yallop/camlp4,yunxing/ocaml,msprotz/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,msprotz/ocaml,yunxing/ocaml,chambart/camlp4,yunxing/ocaml,eliberis/ocaml,hhugo/camlp4,gerdstolpmann/ocaml